Management of mango hoppers in orchards

Management of mango hoppers in orchards
Mango hoppers are the most serious pests of mango.
Hoppers have small sized wedge shaped body. Both nymphs and adults suck the sap from tender leaves, buds, flowers, flower stalk and fruits.
Severely infested leaves become curled and inflorescences get dried. In addition to direct damage, hoppers excrete honeydew on the infested plant parts which encourages the growth of fungal pathogen that form a sooty mould on the infested areas.
Favourable season
They are present throughout the year but are abundant only during the flowering season. The nymphs mature during June to October (feed and breed on the vegetative shoots) and January to March (breed on the flowers and inflorescence).
Egg laying
Adult female lays about 200 eggs singly by penetrating them into the midrib of the young leaves, shoots, flower stalks and unopened flowers.
Eggs are dull white in colour initially which later turn into light brown. The incubation period varies from 4 to 8 days.
After hatching from eggs, the nymphs are pinkish in colour which later turn into pale brown with prominent red bulged eyes along with long black coloured bristles on abdomen.
Nymphal period is 10-14 days. Female can be identified with the sickle shaped ovipositor. Adult longevity varies between three and four days.
Pest management
Avoid dense planting. Adopt resistant varieties and avoid susceptible varieties such as Baneshan, Chinnarasam, Bangalora, Khadar, Gaddemar, Rumani and Himayuddin ( Padiri, Neelam, Mulgoa, Peter and Sindura varieties are highly susceptible).
Orchards must be kept clean by ploughing and removal of weeds.
Remove over crowded, overlapping and infected branches.
Spray Phosalone 35 EC 1.5ml/ litre (or) Carbaryl 50WP 3gm/litre (or) Monocrotophos 36 WSC 1.25 ml/ litre.
Two rounds, first at the time of panicle emergence and the second two weeks later.
Spray 3 per cent neem oil or neem seed kernel powder extract 5 per cent.
M. KANNAN, M. KALYANASUNDARAM & P. SIVASUBRAMANIAN
TAMIL NADU AGRICULTURAL UNIVERSITY, COIMBATORE,

Management of bacterial wilt in tomato

Management of bacterial wilt in tomato
Diseases are a major hurdle in tomato cultivation, both under controlled and field conditions.
Among them bacterial wilt is most devastating on tomato causing yield losses up to 90 per cent.
The disease is also known as southern bacterial blight or solanaceous wilt. Rapid and complete wilting of normal grownup plants is a characteristic symptom of bacterial wilt.
During warm and wet climatic conditions most conspicuous symptom of sudden drooping of leaves, without yellowing, often accompanied by rotting of the stem are seen. The roots appear healthy and well developed. Cultural management
The disease can be kept under check if crop rotations are followed with crops such as maize, ragi and okra, since they can reduce the pathogen population significantly.
Soil solarisation combined with fumigation reduces the pathogen considerably.
Destruction of weeds, collateral hosts and other off season hosts will reduce the innoculum potential. Application of sawdust
Application of sawdust, peatmoss are efficient in reducing the incidence.
Application of nitrite form of fertilizers is also capable of reducing the bacterial population.
Calcium concentration in soil should be increased to have better control of wilt disease.Chemical control
Soil treatment with chloropicrin, methyl bromide or mixture of both were found effective in retarding the wilt development.
Application of bleaching powder (15kg/ha) has also been found effective against this disease.
Seedling dip with streptocycline avoids early invasion and infection by the pathogen through wounds formed during transplanting.
Bacterinol-100 can be used as dry seed dresser, for nursery spray and field application. Streptomycin sulphate or oxytetracycline when sprayed at 200ppm at 7 days interval provides good control.
Tomato varieties such as Arka Abha, Sonali, DPT-38 and Arka Alok which are resistant to bacterial wilt can be used for cultivation.Biological management
Several biological control agents such as Pseudomonas fluorescens, Bacillus licheniformis, B. cereus, B. subtilis and mycorrihiza are very effective in delaying and reducing the wilt development.
Mallikarjun Y
, Kenganal
& Byadgi, A. S.
Department of Plant
Pathology, UAS, Dharwad